Magnetic Clasp

ABSTRACT

Method and apparatus for affixing magnets to objects such as jewelry clasps. In one embodiment the magnet is secured in a single piece setting. When attached to the other half of the clasp, there is a wall between the magnets, enabling the two clasp halves to be mated during drying of the glue. In another embodiment stepped magnets are used, which are preferably further secured in the clasp by mechanical means such as prongs or bezels, so that the resulting fixation is permanent unless the housing itself is deformed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of filing of U.S. Provisional Patent Application Ser. No. 60/897,974, entitled “Magnetic Closures for Jewelry and Other”, filed on Jan. 29, 2007, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention (Technical Field)

The present invention relates to methods and apparatuses for securing magnets in clasps, fasteners, or closures for jewelry (such as a necklace or bracelet) or other uses, including but not limited to a belt, bag or purse, or clothing toggle.

2. Background Art

Note that the following discussion refers to a number of publications and references. Discussion of such publications herein is given for more complete background of the scientific principles and is not to be construed as an admission that such publications are prior art for patentability determination purposes.

Magnets have become popular for use in jewelry and accessories, both in closures and to attach interchangeable decorative elements. A common complaint is that when the magnets are fixed in place with glue, they tend to fall out over time, which typically precludes their use in fine jewelry. In general, the use of glue to hold magnets in metallic housings is a poor option. Gluing metal to metal often fails over time, and is messy and time consuming, requiring up to 24 hours for the glue to fully cure. If any glue is left around the magnet, or if excess glue causes the magnet to tilt slightly, it may interfere with the apposition of the two magnets. Additionally, the force which pulls the magnets together also acts to pull them out of their settings (and fatigues the glue holding them in place) each time they are separated. Additionally, if the two halves of the clasp are mated together while the glue if drying, there is a significant chance that the pieces will end up glued together, rendering the clasp useless.

Langer (U.S. Pat. No. 5,845,373) addresses the deficiency of gluing magnets, but in addition to the magnet the clasp described requires two elements, the clasp and the platelet, and these two elements must be extremely precisely manufactured or machined in order to achieve the pressure fit which Langer specifies. Similarly Eisenpresser (U.S. Pat. No. 5,974,634) describes a magnetic button which utilizes a similar approach, with the need for 2 elements in addition to the magnet, which must be fitted into each other with precision.

SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)

The present invention is a clasp comprising two magnetically attractable clasp members, each member comprising a housing, a stepped compartment within the housing, a stepped magnet disposed in the compartment, and at least one securing device integrated with the housing. The securing device is preferably selected from the group consisting of a prong and a bezel. A portion of the at least one securing device is preferably bent over the magnet after the magnet is disposed in the compartment. The housing preferably further comprises an attachment device for attaching the housing to an object. The stepped compartment preferably prevents the magnet from moving in a first direction. The securing device preferably prevents the magnet from moving in a second direction substantially perpendicular or substantially opposite to the first direction. The housing optionally comprises an opening substantially aligned with a surface of the magnet. The housing preferably comprises a structure for aligning a first clasp member with a second clasp member. The structure preferably prevents entanglement of a strand of objects with the first clasp member. The magnet preferably comprises a first face which is attracted to a second face of a magnet in another clasp member. The first face is optionally located interior to the housing.

The present invention is also a clasp comprising two magnetically attractable clasp members, each member comprising a housing, a stepped magnet disposed in the housing, the stepped magnet comprising a raised central portion, and at least one prong attached to the housing, a portion of the prong bent over an edge portion of the stepped magnet, wherein the bent portion of the pong does not extend substantially above the raised central portion of the stepped magnet. The housing preferably comprises a registration device to align a first clasp member with a second clasp member. The housing preferably further comprises a handle to aid in separating the first clasp member and the second clasp member.

The present invention is also a clasp comprising two magnetically attractable clasp members, each member comprising a housing and a compartment for receiving a magnet, the compartment comprising a wall parallel to an attracting face of the magnet and separating the face from an exterior of the housing, wherein the magnet is secured in the compartment. The magnet is preferably secured in the compartment by a prong, a bezel, or adhesive. A portion of the prong or bezel is preferably bent over the magnet. If adhesive is used, the housing of a first clasp member is optionally magnetically attached to a second clasp member during curing of the adhesive. The wall preferably prevents uncured adhesive from reaching an exterior of the housing.

Objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. In the drawings:

FIG. 1 shows a pair of flat disc-shaped magnets.

FIG. 2 shows a clasp device incorporating the disc magnets in FIG. 1 housed in bezel type settings.

FIG. 3 shows a pair of rectangular magnets.

FIG. 4 shows the magnets of FIG. 3 incorporated into a belt buckle or closure in which the magnets will be held in place with prongs, behind a complete wall.

FIG. 5 shows the closure of FIG. 4 with the prongs bent over to hold the magnets in place.

FIG. 6 shows a pair of rectangular stepped magnets.

FIG. 7 shows the magnets of FIG. 6 incorporated into a clasp or closure in which they will be fixed in place with prongs.

FIG. 8 shows the clasp or closure of FIG. 9 with the prongs bent over to hold the magnets in place.

FIG. 9 shows a pair of round stepped magnets.

FIG. 10 shows a clasp utilizing the magnets of FIG. 9.

FIG. 11 is a cross section of one half of the clasp shown in FIG. 10.

FIG. 12 shows a different setting utilizing the rectangular stepped magnets of FIG. 6, wherein the magnets are held in place in a different orientation, using prongs.

FIG. 13 shows the setting of FIG. 12 with the prongs after they have been pushed over to hold the magnet in place.

FIG. 14 shows the setting of FIG. 13 mated with the other half of the clasp.

FIG. 15 shows a jewelry clasp of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (BEST MODES FOR CARRYING OUT THE INVENTION)

The present invention comprises a clasp or other closure with two magnetically attractive members. Each half or member preferably comprises a single unit, which is simple and inexpensive to produce, and preferably comprises a pocket or setting to accommodate a magnet. Prongs, a bezel, glue, or other securing means may be used to secure the magnet in position.

Each magnet may be placed behind a complete wall, which remains interposed between the two members when the clasp is in the closed position. In this embodiment, the magnets can either be set without glue (for example using prongs or a bezel). Alternatively, if glue is used, the clasp of the present invention is advantageous over other glue-based clasps because: excess glue will not disrupt the mating of the two members; the two halves of the clasp can be mated together while the glue is drying, without the risk of the two halves becoming glued together; and the glue bond is subject to less stress, since each time the halves of the clasp are separated, the magnet is drawn further into its setting, rather than being pulled out of it. Because the existence of the wall reduces the attractive force of the magnets, magnets with larger volumes may be used.

However, when a small application is desired, the size (and weight) of the magnets becomes an issue. In this case, or in other applications as desired, an embodiment of the present invention comprises a stepped magnet, preferably set behind a partial wall, which preferably allows part of each magnet to be in direct alignment with its counterpart in the other member. The magnets may be round, cylindrical, rectangular, or comprise any other shape. The magnets can be set using one or more prongs or a bezel without interfering with the apposition of the elevated “step” section of the magnets in the closed position. Using stepped magnets, portions of the two magnets come into direct contact in the closed position, but because of the partial wall, they can still be fixed in place using prongs or bezels. The invention described herein preferably comprises a one piece setting for each magnet, and because either prongs or a bezel or glue may be used to restrain the magnet, less precision is required, making manufacturing simpler and cheaper.

As used throughout the specification and claims, “stepped” means comprising at least one offset or part resembling a step, or comprising a first portion which has a different diameter or dimension than a second portion.

The use of prongs, bezels, or other mechanical means to secure the magnets in some embodiments of the present invention is enabled because the magnets are preferably set from the back, or alternatively the magnet is stepped in shape. The use of these types of mechanical settings is precluded in other magnetic clasps because they would interfere with the apposition of the two members if used from the front, or with a non-stepped magnet.

The materials used in the embodiments described herein are preferably metallic, either precious or base, and may optionally be plated. The invention may alternatively comprise any material, including but not limited to metal, plastic, wood, or epoxy resin.

FIG. 1 shows a pair of simple cylindrical or disc shaped magnets. Arrows 17A and 17B represent the force of attraction between the magnets. In all cases, the magnets may be any form of permanent magnet, including but not limited to NeFeB magnets. Also in all cases, one magnet may be replaced with a ferrous material to which the remaining magnet would be attracted.

FIG. 2 shows a clasp or closure which incorporates the magnets shown in FIG. 1. Bezels 4A and 4B accommodate the disc shaped magnets of FIG. 1. The bezels may optionally have at least a portion of their edges bent inwards, to hold the magnet 1B in place (the other magnet is not shown in the figure). The magnets may alternatively be glued or pressure fit into the bezels. Because mating walls or faces 8A, 8B separates the halves of the clasp, gluing requires much less precision than if the magnets met face to face, since excess glue, or minor misalignment of the magnets will not cause disruption of mating faces 8A and 8B. In addition, because of the use of complete walls between the halves, the magnets can be glued in place while the halves of the clasp are mated together, without the risk of inadvertently gluing the two halves together. Bezels 4A and 4B may optionally be replaced with a plurality of circumferential prongs. Elements 11A, 11B and 7A, 7B serve to “register” one half of the clasp relative to the other half. Many alternative means may be used to accomplish this, such as bumps on one half with corresponding wells on the other half, or pegs on one half which fit in to holes on the other half.

Cavities 13A, 13B may comprise any shape and preferably enable the insertion of the magnets, and preferably decrease the weight of the clasp. Outer walls 10A, 10B of the clasp can be of any desired shape, thickness, or weight. Ring 9B connects the clasp to any decorative or functional material. The other half of the clasp may also comprise a similar ring (not shown). In the case of a necklace, this may comprise a strand of pearls or beads, for example. Ring 9B can be in any orientation, and may be of any shape. Ring 9B may optionally comprise a toggle, which permits it to rotate in a circle. The material of the necklace, or bracelet, or anklet, or belt could also be attached by other means known in the art.

FIG. 3 shows a pair of flat rectangular magnets. Arrows 22A and 22B represent the attractive forces (polarities) of the magnets. FIG. 4 shows the magnets from FIG. 3 utilized in a belt buckle type closure. Magnets 21A, 21B are preferably situated in pockets shaped to accommodate them and held in place with prongs 26A, 26B, 26C, 26D. The number, location, and shape of the prongs may be varied, as can the configuration of walls 28A, 28B, 28C, as long as the prongs are adequate to hold the magnets in place when the prongs are bent over, as shown in FIG. 5. The prongs prevent the magnets from falling out of the clasp, so the clasp does not need a top face to enclose the magnets. This reduces weight and simplifies manufacturing. Mating faces 25A, 25B may comprise a means of registering the two halves of the closure, such as bumps on one half and wells on the other, as described for FIG. 2. Bars 27A, 27B may be used to attach a wide element such as a belt. As described above, because there is a complete wall interposed between the two members, glue can also, or alternatively, be used to fix the magnets in their settings, instead of prongs.

FIG. 6 shows a pair of stepped rectangular magnets, each of which may be formed as a single piece such as by sintering or machining, or may alternatively use a tiny screw and nut through the center, or other fastening means, to fasten two magnets of different sizes together. FIG. 7 shows a clasp or closure using the magnets in FIG. 6. Magnets 40A, 40B are preferably located in depressions or pockets of corresponding shapes, with cutouts in the central walls that allow the central portions of the magnets to come in contact with one another when the clasp is in the mated or closed position. The shapes of the halves of the clasp can be in any configuration found to be esthetically pleasing. It is further noted that the two halves do not have to be symmetrical; for esthetic reasons, it might be desirable for one half to be of a different size or configuration than the other member. Prongs 42A, 42B, 42C, 42D are preferably bent over to hold magnets 40A, 40B in place, as shown in FIG. 8. Rings 47A, 47B preferably serve to attach decorative or functional material such as a necklace, bracelet, anklet or belt to the clasp.

FIG. 9 shows a pair of stepped round magnets. FIG. 10 shows a clasp for accommodating the magnets shown in FIG. 9. Bezels 70A, 70B secure the magnets in place. Opening 75 is preferably smaller in diameter than bezel 70B and accommodates the smaller diameter portion of the magnet. FIG. 11 is a cross section of one half of the clasp of FIG. 10, showing magnet 60 in its setting. Edge 64 of bezel 70B may optionally be bent over to help secure magnet 60. Bezel 70B may alternatively be replaced by one or more prongs which can be bent to secure magnet 60.

FIG. 12 shows clasp half 76 which receives the stepped magnet of FIG. 6 in a horizontal orientation. Raised wall 85 and recessed wall 87 are disposed within housing 83 and preferably serve to keep the halves of the clasp in “registration” with one another, as well as preventing horizontal displacement of the halves of the clasp once it is mated. Specifically, raised wall 85 is preferably designed to fit into the corresponding recess formed by the recessed wall on the other half of the clasp, and the raised wall on the other half of the clasp is preferably designed to fit into the recess formed by recessed wall 87. Magnet 78 is preferably held in place by prongs 81A, 81B, 81C, 81D, which are preferably bent over the stepped portion 80 of magnet 78 as shown in FIG. 13. Structure 82 (and a symmetrically located structure not visible in this projection) preferably serves to hold magnet 78 in place in a horizontal plane. The prongs, once bent over, prevent lateral movement, as well as holding the magnet against the back of clasp half 76.

FIG. 14 shows the embodiment of FIGS. 12 and 13 with the two halves of the clasp in the mated or closed position. This type of clasp may be difficult to open, so a handle may optionally be provided to aid in that regard. In this embodiment, one handle comprises segments 86A, 86B, 86C, and the other handle comprises segments 88A, 88B, 88C; the handles can be grasped to help open the clasp. Terminal segments 86C, 88C also preferably comprise an opening which provides a means to attach decorative or functional material to the clasp. The handle may comprise any desired shape or size. Although the handles are shown on opposite sides of the clasp in the figure, they may be located anywhere on the clasp relative to one another.

The embodiment of FIG. 15 is a clasp especially suitable for jewelry, such as a necklace, bracelet, or anklet. Rings 203A, 203B preferably prevent a strand or strands of beads, pearls, or the like from becoming tangled in the clasp. The strand or strands of decorative material can be connected to bar 205 either by tying off, using crimp beads, or other means known in the art. The top of wall 206 preferably extends to form prongs 204, 204′ which can be bent over, to hold stepped magnet 207 in place. Walls 208A, 208B preferably comprise an opening to accommodate the stepped portion of magnet 207. In order to assist in separating the clasp once joined, indentation 209 is preferably provided to accommodate a finger nail or the like. Clasp ends 201A and 201B preferably fit behind rings 203B and 203A so that the clasp appears quite seamless when the halves are mated together.

Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover all such modifications and equivalents. The entire disclosures of all patents and publications cited above are hereby incorporated by reference. 

1. A clasp comprising two magnetically attractable clasp members, each member comprising: a housing; a stepped compartment within said housing; a stepped magnet disposed in said compartment; and at least one securing device integrated with said housing.
 2. The clasp of claim 1 wherein said at least one securing device is selected from the group consisting of a prong and a bezel.
 3. The clasp of claim 1 wherein a portion of said at least one securing device is bent over said magnet after said magnet is disposed in said compartment.
 4. The clasp of claim 1 wherein the housing further comprises an attachment device for attaching said housing to an object.
 5. The clasp of claim 1 wherein said stepped compartment prevents said magnet from moving in a first direction.
 6. The clasp of claim 5 wherein said securing device prevents said magnet from moving in a second direction substantially perpendicular or substantially opposite to said first direction.
 7. The clasp of claim 1 wherein said housing comprises an opening substantially aligned with a surface of said magnet.
 8. The clasp of claim 1 wherein said housing comprises a structure for aligning a first clasp member with a second clasp member.
 9. The clasp of claim 8 wherein said structure prevents entanglement of a strand of objects with said first clasp member.
 10. The clasp of claim 1 wherein said magnet comprises a first face which is attracted to a second face of a magnet in another clasp member.
 11. The clasp of claim 10 wherein said first face is located interior to said housing.
 12. A clasp comprising two magnetically attractable clasp members, each member comprising: a housing; a stepped magnet disposed in said housing, said stepped magnet comprising a raised central portion; and at least one prong attached to said housing, a portion of said prong bent over an edge portion of said stepped magnet; wherein said bent portion of said pong does not extend substantially above said raised central portion of said stepped magnet.
 13. The clasp of claim 12 wherein said housing comprises a registration device to align a first clasp member with a second clasp member.
 14. The clasp of claim 13 wherein said housing comprises a handle to aid in separating said first clasp member and said second clasp member.
 15. A clasp comprising two magnetically attractable clasp members, each member comprising: a housing; and a compartment for receiving a magnet, said compartment comprising a wall parallel to an attracting face of said magnet and separating said face from an exterior of said housing; wherein said magnet is secured in said compartment.
 16. The clasp of claim 15 wherein said magnet is secured in said compartment by a prong, a bezel, or adhesive.
 17. The clasp of claim 16 wherein a portion of said prong or bezel is bent over said magnet.
 18. The clasp of claim 16 wherein said housing of a first clasp member is magnetically attached to a second clasp member during curing of said adhesive.
 19. The clasp of claim 16 wherein said wall prevents uncured adhesive from reaching an exterior of the housing. 